1. Field of the Invention
This invention relates to a assembly for removing hydrophilic contaminants such as sodium, a method of the same, and an apparatus for producing phenol, which is utilized for removing the hydrophilic contaminants such as the sodium included in an oil-state liquid in each process of the plant as the phenol producing apparatus.
2. Description of the Related Art
In a phenol plant for producing the phenol, recently, a cumene method of which reaction condition is moderate and of which process can be completely automated is suitable for the continuous mass production as well as has excellent profitability, so that the method becomes a major phenol producing method in the world.
In the process of producing phenol by the cumene method, alkali such as sodium carbonate is added in the neutralization process after the oxidation of the cumene or in the neutralization process after cumene hydroperoxide which is obtained by oxidation of the cumene being disintegrated by an acid material.
However, the alkali used for the neutralization as described above may result in various problems downstream of the neutralization process. That is, when the oil-state liquid flowing in the process is heated by a reboiler which is equipped in a concentration tower or a distillation tower provided downstream of each neutralization process, the disadvantage that the sodium used for the neutralization is extracted and the fouling (clogging-up) in tube of reboiler tales place.
The fouling of the reboiler as described above causes a lowering in heat efficiency of the reboiler or an increase of chest pressure, so that the cleaning shut down of the reboiler have to be done, stopped each apparatus of the plant in every fixed period such as once in two or three months to maintain the function of the reboiler. Resultingly, it causes the lowering of productivity as well as the disadvantage that the work of the cleaning shut down itself is undesirable because of the hazardousness of the oil-state liquid to be dealt with such as the cumene.
There has heretofore been adopted the removing alkali such as sodium from the process by each kind of fluid treatment device.
As one of the fluid treatment devices, a filter device of so-called filling filter member system in which the filter member such as glass wool is filled in a drum and so on.
There is also a known filter device in which a cartridge type fluid filtration element called a depth-type element is attached. The cartridge type fluid filtration element is generally constructed in such a way that a filter member such as glass wool is wounded with almost uniform thickness as layers around the exterior of a porous holding cylinder, and doughnut disk-like end plates are fixed to both end surfaces of the filter member. There has been adopted a means for fixedly sealing the end plates to the filter member with a synthetic resin bonding agent such as a epoxy resin.
However, the method for removing alkali such as sodium by the filter device of filling filter member system as described above involves a disadvantage that the filter member such as glass wool tends to be melted as it has non-alkali resistance, whereby it can not maintain the performance as the filter member for a long duration.
In the filling filter member system, the filter member is directly filled in the drum and so on, so that the density of the filter member becomes irregular and the sufficient performance can not be obtained. Furthermore, the oil-state liquid is leaked from the gap formed at the contacted portion of the filled filter member and the drum body, so that the alkali such as the sodium can not be removed sufficiently.
In the method of removing alkali by the filter device in which the cartridge type fluid filtration element is attached, the irregularity of the density of the filter member can be improved because the filter member is wound on the exterior of the porous holding cylinder, however there is a disadvantage that the synthetic resin bonding agent such as the epoxy resin used for fixing the end plates to the filter member is melted due to acetone, cumene, cumene hydroperoxide, and phenol which are dealt with in the plant, so that the end plates can not be sealed completely to the filter member.
The object of the present invention is to provide an assembly for removing hydrophilic contaminants and the method of the same which can remove the hydrophilic contaminants such as sodium included in the oil-state liquid positively, as well as maintain the fixed removing performance for a long duration, and to provide a phenol producing apparatus which has high rate of operation.